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Car Spring.`

No. 67.897. `Pagg;in tepl Aug.'240.1867,'

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JOHN S. MILLER, 0E SPRINGFIELD, MASSACHUSEFIS,l ASSIGNOR TO HIM SELF AND L. L. DAVIS, OF SAME PLAGE.

Letters Patent No. 67,897, datecZAugust 20, 1867; antedated August 5, 1867.

IMPROVED GAR-SPRING.

TO ALL WH OM IT MAY CONCERN:

:Be it known that I, JOHN S. MILLER,'-of Springfield, Hampden county, Commonwealth of Massachusetts, have invented a new amb useful Car-Spring; and I do hereby declarethat the following is a full and exact descriptionthereof, reference being had to the accompanying drawings, and to the letters of reference vmarked thereon. In the drawings- Figurel represents a section view of my invention, and

Figure 2 a side view of the same with a part broken out.

My invention consists of a car-spring whose principle is the compression of the air for a cushion. This is arranged in a peculiar manner, which I will now describe. Y

I form my spring of a cylindrical case, A, made of suitablematerial, and having a plunger, B, working in it; the case A being attach-ed to the runninggear, and the plunger to thebody of the car. The plun er B is made to fit closely in the case, but is not cushioned merely by confined air between it and the bottomA of the cylinder, but that part of the cylinder is filled with a rubber case, C, which is made to t'the bore oi' the cylinder, and is hollow and perfectly air-tight, so that when it is compressed' by the'plunger the air inside of the rubber case is compressed withit. Thus I obtain the full elasticity of the air confined, and that of the rubber beside, for my' spring. By this arrangement I have a perfect spring, and4 one that never loses its elasticity, there being no possible outlet for -the air in the case of rubber, consequently the -spring is always-of theisame strength. It' by any possible means the rubber cushions should be damaged, it only requires that a new one of rubber be dropped in the place of the old one, the plunger being easily taken out. The rubber cushion is, bowever, very durable, for, having the same pressure always onthe outside'and inside, except a slight difference in the movement of 'compression or reaction, there is nothing which could cause either wear or fracture, and in order to -give greater security against this it is formed much thicker at the corners, where it would be most liable to crack.

New, having described my invention, what l claim as new, and desire to secure by Letters Patent, is-

The combina-tion and'arrangement ofthe spring for cars, 85e., formed of a cushion of air enclosed Ain' a case, C, of rubber, or similar elastic material, placed within a cylinder, A, operated upon by a pistoia-B, thewhole constructed and operating substantially'as described. y

JOHN S. MILLER.

Witnesses:

J. B. GARDINER, Enw. H. HYDE; 

